Domain names identify unique web sites and email addresses. They are also referred to as URLs. The specification includes entire domain structure in host.site.domain.name format. Site refers to sub-domain, domain refers to second-level domain, and name refers to top-level domain. The host is a computer, router, or workstation that uses a protocol of Internet Protocol family to transport hypertext documents across Internet. Hyper Text Transport Protocol (HTTP) is an example.

The World Wide Web is the sub-domain, and is a hypertext-based client/server model for finding and accessing resources on the Internet. It is a computer network consisting of a collection of Internet sites featuring information through text format, graphics format, sound and animation form. Users access these sites through hypertext transfer protocol. Domain names link to web sites on the World Wide Web.

A second-level domain represents an actual domain, which is the company or the owners name, and is unique. Top-level domain (TLD) is the end part the web address, such as .com.net, or .org. Also called the ""extension"", it indicates the core activity of the organization. The Internet Assigned Numbers Authority (IANA) currently classifies top-level domains in three types: country code, generic, and special domain names. Country-code top-level domains such as .in.uk.ca, and .fa end with two-letter extension. A particular class of organizations uses generic top-level domains. The third is the infrastructure top-level domain.

Computers record or identify websites numerically with IP addresses. Since its difficult to remember IP addresses, a system called Domain Name system (DNS) was created to translate IP addresses to domain names. Domain names are not case-sensitive.

To build a successful online business, it is essential to own a domain name. It increases a websites visibility. Customers or targeted prospects can locate the company online and reach out for its services. A highly relevant domain would establish credibility and professionalism.